I'm sensing from all of your questions, that you may not have a lot of experience in working on autos, and a little hesitant about jumping in and taking the hvac apart. I'm not sure you will be able to find someone, who can walk you through step by step how to do this repair specific for your year/vehicle/model. What you may want to seriously consider, is purchasing a set of factory service manuals for your vehicle, which you could get from [ Link Not Allowed ] They are very detailed, giving step by step instructions on repairing everything on the car, with pictures galore.

The way some of the repairs are now adays, you can spend hours trying to figure out how to do something, where the instructions can take away all of that uncertainty.